| abstract |
(57) [Abstract] [Purpose] To provide a simple regeneration method for phosphorus, molybdenum, and vanadium-based deterioration catalysts. [Structure] A phosphorus-, molybdenum-, vanadium-based deterioration catalyst used for producing methacrylic acid by vapor-phase oxidation of methacrolein is heat-treated at 300-410 ° C. with an oxidizing gas containing at least 0.1% by volume of oxygen. . The deteriorated catalyst is treated as it is packed in the reaction tube. [Effect] The activation is regenerated to a considerable level by a very simple method. |